If this app turns the entire screen black, this probably means WebGL is not supported :)
Black holes don't really "suck in" light. Whatever falls onto the black hole itself gets deleted, of course – but otherwise, it bends light rays towards its center. That's why the app shows distortion + black circle in the in middle in the camera mode.
The event horizon for even the smallest black hole is in the scale of kilometers. If the user is a meter away from the black hole light isn't going to move away from the center of it to your camera.